
		.navtop{
			position: fixed;
			top: 0;
			height: 100px;
			width: 100%;
			z-index: 100;
			background-image: linear-gradient(rgba(0,0,0,0.9),rgba(0,0,0,0));
			transition: height 0.3s;
			overflow: hidden;
		}
		.navtop:hover{
			height: 285px;
			background-image: linear-gradient(rgba(0,0,0,1),rgba(0,0,0,0.2));
		}
		.navtop:hover .div2{
			display: block;
		}
		.a1{
			text-align: center;
			text-decoration: none;
			float: left;
			width: 80px;
			margin: 0 60px;
			margin-top: 30px;
			color: white;
			font-family: "黑体";
			font-size: 30px;
			transition: color 0.5s;
		}
		.navul a{
			text-align: center;
			text-decoration: none;
			color: white;
			transition: color 0.3s;
		}
		.navul a:hover{
			color: rgb(115,201,229);
		}
		.a1:hover{
			color: rgb(115,201,229);
		}
		.div1{
			margin: 0 auto;
			width: 800px;
			height: 120px;
		}
		.div2{
			position: relative;
			bottom: 50px;
			margin: 0 auto;
			width: 800px;
			display: none;
		}
		.navul{
			float: left;
			width: 80px;
			margin: 0 60px;
			margin-top: 30px;
			list-style-type: none;
		}